Data Engineering Data Warehouse Modeling Questions and Answers

Question 1

A retail company wants to analyze sales performance.
Their data model includes a central 'Sales' table with measures like 'quantity_sold' and 'total_amount'.
This table is linked to other tables such as 'Product', 'Store', and 'Date' which contain descriptive attributes.
What is the primary role of the 'Sales' table in this dimensional model?

Accepted Answer

To store quantitative measures of business events.

Answer

To provide descriptive context for the business process.

Answer

To maintain historical changes of dimensional attributes.

Answer

To normalize hierarchical data to save storage space.

Question 2

A data engineering team is designing a data warehouse for a large financial institution. They need to prioritize storage efficiency and data integrity due to complex, multi-level hierarchies in their customer and account dimensions. Query performance is a secondary concern. Which schema design would be most appropriate for this scenario?

Accepted Answer

Snowflake Schema

Answer

Star Schema

Answer

Data Vault

Answer

Flat Denormalized Model

Question 3

A company needs to track the complete history of changes to its customer dimension, specifically their assigned sales representative. When a customer is reassigned to a new representative, a new record for that customer should be created with the updated information, and the previous record should be preserved. Which Slowly Changing Dimension (SCD) type should be implemented?

Accepted Answer

SCD Type 2

Answer

SCD Type 1

Answer

SCD Type 0

Answer

SCD Type 3

Question 4

Which of the following best describes a data mart?

Accepted Answer

A subset of a data warehouse focused on a specific business line or department.

Answer

A large, centralized repository for all enterprise data from various sources.

Answer

A schema design that uses multiple fact tables sharing common dimensions.

Answer

An un-modeled, schema-on-read repository for raw structured and unstructured data.

Question 5

In a data warehouse model for an e-commerce platform, analysts need to analyze sales transactions and website clickstream data together. Both datasets share common dimensions like 'Customer', 'Product', and 'Date'. Which schema design is specifically intended to model this scenario of multiple business processes sharing dimensions?

Accepted Answer

Fact Constellation Schema

Answer

Star Schema

Answer

Snowflake Schema

Answer

Normalized Schema

Question 6

When designing a dimensional model, what is the primary advantage of using a Star Schema compared to a Snowflake Schema?

Accepted Answer

Faster query performance due to fewer joins.

Answer

Reduced data redundancy and lower storage costs.

Answer

Simplified data maintenance and updates.

Answer

Improved data integrity through normalization.